This blog provides stories that Denyse O'Leary, a Toronto-based journalist, has found to be of interest, as she covers the growing intelligent design controversy. It supports her book By Design or by Chance? (Augsburg 2004). Does the universe - and do life forms - show evidence of intelligent design? If so, Carl Sagan was wrong and so is Richard Dawkins. Now what?

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Thursday, November 26, 2009

Human evolution: FoxP2 and speech

A friend warns, wisely in my view, that we be skeptical about vast claims made in the popular science press about human evolution.

One paper asserts that FOXP2 was probably involved in the evolution of speech and language, but another paper has cautioned about being too hasty in making this conclusion.

Well, after the "Ida" fossil took in Michael Bloomberg, I'd be cautious about anything evolutionary biologists say. So should Bloomberg, herafter.

For what it is worth, I also don't believe that Flores man is really a separate human species, because I have seen proportionately formed women on the streets of Toronto who were not more than one metre tall. But it's just the sort of squabble no one cares about, and figures like Michael Bloomberg do not get involved.

Here's one assessment from the science literature: “The finding that FOXP2 is critical to speech and language does not by itself demonstrate the role of this gene in the origin of human speech, because the function of FOXP2 could have remained unchanged during human evolution while other speech-related genes changed.” (Jianzhi Zhang, David M. Webb and Ondrej Podlaha, “Accelerated Protein Evolution and Origins of Human-Specific Features: FOXP2 as an Example,” Genetics, Vol. 162:1825–1835 (December 2002).)

No-one should imagine that the development of language relied exclusively on a single mutation in FOXP2. They are many other changes that enable speech. Not least of these are profound anatomical changes that make the human supralarygeal pathway entirely different from any other mammal. The larynx has descended so that it provides a resonant column for speech (but, as an unfortunate side-effect, predisposes humans to choking on food). Also, the nasal cavity can be closed thus preventing vowels from being nasalised and thus increasing their comprehensibility. These changes cannot have happened over such a short period as 100,000 years. Furthermore the genetic basis for language will be found to involve many more genes that influence both cognitive and motor skills

One thing to keep in mind is that human language is also governed by the need to communicate things that no ape would need to communicate. So understanding language requires understanding mind.

Assume I have a car. Assume the mechanic at Canadian Tire is trying to explain to me what is wrong with my car.

I don’t know much about cars but I know that the car is not working. I accept his explanation and his promise to fix it. And my big question is, “What will this cost?”

That question assumes an exceedingly complex system of social transactions around that unpleasant subject, money.

I’d also like to know, “When will the car be ready?”

“Some time” won’t cut it around here. I need to know when to show up again on the transit, pay, and drive the car away. I have other things to do. So does the mechanic. He even has a time sheet. So do I.

But that assumes a “clock” view of time, again a complex human idea.

Also, that car is only drivable due to roads and bridges, which are again complex constructions, involving many social transactions that require language.

To me, the nonsense around ape “language” fails to distinguish the way in which human language conveys ideas about things that are meaningless in principle to animals.

If I were an ape, maybe I could solve all my problems by aiming a coconut at another ape’s head and then swinging rapidly through the trees.